Justin BieberDNA Test Is In the Bag

11/21/2011 10:23 AM PST

Justin Bieber -- DNA Test Is In the Bag

Justin Bieber took a DNA test on Friday night in New Jersey, and now it's baby mama's move ... TMZ has learned.

We've learned ... Justin took the test at a lab under "very controlled circumstances." We're told there is a solid chain of custody, so it's going to be hard for Mariah Yeater or her lawyer to challenge it.